A B C D E F G H I K L M N O P R S T U V W Z

The HVAC (Heating, Ventilation, Air Conditioning) industry can be a maze of unfamiliar acronyms and industry terms. Klondike Air Conditioning & Heating Experts of Orange County, CA wants our customers and prospective customers to be knowledgeable and able to understanding of these terms when dealing with people in the industry.

AC (Alternating Current): A type of current where the polarity is perpetually reversing, causing the directional flow in a circuit to reverse at regular intervals.

ACCA: Air Conditioning Contractors of America

Acoustical: Relating to sound, the science of sound, or a sense of hearing.

AFUE (Annual Fuel Utilization Efficiency): A measurement used to rate furnace efficiencies by dividing the ratio of heat output by heat input.

AGA: American Gas Association, Inc.

Air Cleaner: A device that removes allergens, pollutants and other undesirable particles from air that is heated or cooled.

Air Conditioner: A device that changes humidity levels, temperature or quality of air.

Air Filtration System: A device that removes allergens, pollutants and other undesirable particles from air that is heated or cooled.

Airflow Volume: Measured in cubic feet per minute (cfm), this is the amount of air circulated in a space.

Air Handler: Parts of a system including the fan-blower, filter and housing.

AHRI: Air Conditioning, Heating and Refrigeration Institute

Allergen: A substance that causes an allergic reaction. It includes dust, pollen, pet hair and dander, dust mites, mildew, lint, fungus, most tobacco smoke, cooking grease and bacteria.

All-In-One or Packaged System: Packaged systems are all-in-one solutions, with most of the components for heating and/or cooling housed in a single cabinet.

ASHRAE: American Society of Heating, Refrigeration and Air Conditioning Engineers

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BTU:  British Thermal Unit. Measures the amount of heat required to raise or lower the temperature of one pound of water one degree Fahrenheit.

BTU/h:  British Thermal Units per hour

Burner:  The device that facilitates the combustion of air and gas.

Burner Orifice:  The opening in the burner through which the gas or fuel passes prior to combustion.

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Capacity:  HVAC capacity is the output produced by the heating or cooling unit and is measured in BTUs per hour.

Celsius:  A temperature scale that registers the freezing point of water as 0° and the boiling point as 100° under normal atmospheric pressure.

CFM (Cubic Feet per Minute):  A measurement of airflow volume.

Charging a System:  Adding coolant, or refrigerant, to an HVAC system.

Clean Air Delivery Rate: Clean Air Delivery Rate (CADR) is the number of cubic feet of clean air that an air-filtration system delivers in a minute.

Communicating Systems: Communicates when to use either the heat and air system. Communicating systems provide a superior level of HVAC home automation with convenience and efficiency throughout its long system life.

Compressor:  A pump that increases the pressure of gas. It is part of the outdoor unit that pumps refrigerant. The compressor maintains adequate pressure to cause the refrigerant to flow in sufficient quantities in order to meet the cooling requirements of the system and your home.

Condensate:  Vapor that is turned into a liquid as its temperature is lowered.

Condenser Coil:  Also an outdoor coil. A device that removes heat from the refrigerant, allowing the refrigerant to be converted from vapor to liquid.

Condenser Fan:  A fan that passes air over the condenser coil to facilitate the removal of heat from the refrigerant.

Control A temperature-control device, typically found on a wall inside the home. It consists of a series of sensors and relays that monitor and control the functions of a heating and cooling system.

CSA:  Canadian Standards Association

Cycling: Refers to the process of an HVAC system turning on and off. Some systems require less cycling than others, leading to higher energy efficiency and less wear on the system.

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DC (Direct Current):  A type of electrical current that only flows in one direction.

Damper:  Found at the exit point of duct work, this plate usually contains grates that can be opened or closed to control the flow of air into a zone.

Degree-Day:  Calculated by subtracting the average outdoor temperature for an area from 65º Fahrenheit. This measurement is used to estimate the amount of heating or cooling a home or building will need.

Dehumidifier:  A device that removes humidity, or moisture, from the air.

Diffuser:  A grille over an air supply duct with vanes that distribute the discharging air in a specific pattern or direction.

DOE:  Department of Energy

Downflow Furnace:  A furnace with an intake on the top and an air discharge at the bottom.

Drain Pan:  Also a condensate pan. As the refrigerant vapor is liquefied, the drain pan collects the condensate and funnels it to the drain line.

Dry Bulb Temperature:  The temperature as measured without the consideration of humidity.

Dual Fuel: Dual fuel refers to a system having the option of two fuel sources to maximize efficiency.

Duct work:  A network of metal, fiberboard or flexible material flowing throughout a space which delivers air from an HVAC unit to the respective zones of a home or office.

Ductless Systems: Made for homeowners who want the same reliable heating and air conditioning as larger homes but with the flexibility to do it in spaces where ductwork is not an option. With ductless systems, an outdoor unit is connected to an indoor unit mounted on a wall or ceiling to provide you and your family the reliable comfort you deserve.

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EER:  Energy Efficiency Ratio

Energy Star: ENERGY STAR is a government-backed program helping businesses and individuals reduce energy costs and protect the environment through superior energy efficiency. It is a voluntary labeling program developed by the U.S. Department of Energy and the Environmental Protection Agency (EPA) in 1992 to promote awareness of energy-efficient products.

Energy Tax Credits: Federal tax credits for qualified HVAC improvements.

EPA:  Environmental Protection Agency

Expansion Valve:  A valve that meters the levels of refrigerant through a temperature or pressure control.

Evaporator Coil:  Also an indoor coil. A device that is designed to absorb heat in the air in order to change the liquid refrigerant that flows through it into a vapor.

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Fahrenheit:  A temperature scale in which water freezes at 32 degrees and boils at 212 degrees at normal atmospheric pressure.

Fan:  A device that creates airflow.

Federal Energy Tax Credits: Federal tax credits for qualified HVAC improvements.

Ferris State University: One of only two institutions in the United States to offer a Bachelor of Science in HVACR.

Filter:  A device that acts like a strainer to remove dirt or undesired particles.

Flue:  A vent that removes the byproducts of combustion from a furnace.

Furnace:  The major component in heating a home. A device that facilitates the combustion of fuel and air to create heat.

Fuse:  A delicate metal strip connecting two parts of an electrical circuit. This strip breaks, or melts, in the event of an excess electrical charge, breaking the electrical circuit.

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GAMA:  Gas Appliance Manufacturers Association

Geothermal Systems: We can’t control the temperature within the earth, but we can use it to our advantage. Geothermal systems tap into the even, steady temperatures underground to regulate your home’s indoor comfort. These systems use less energy and allow you to reduce energy costs and your carbon footprint.

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Heat Exchanger:  A device through which heat is transferred to a cold area or surface.

Heat Gain:  The amount of heat added or created in a designated area.

Heating Coil:  A coil that acts as a heat source for a heating system.

Heat Loss:  The amount of heat subtracted from a designated area.

Heat Pump:  A device used for either the heating or cooling of a space by transferring heat between two reservoirs.

Heat Transfer:  Moving heat from one location to another.

HEPA Filter: A High-Efficiency Particulate Absorbing filter. A HEPA filter removes particles from the air by trapping them as air flows through.

Home Automation: Anything that gives you remote or automatic control of things around your home, including but not limited to your HVAC, lighting or security system.

HSPF (Heating Seasonal Performance Factor):  This factor rates the efficiency of the heating portion of the heat pump.

Humidifier:  A device that adds humidity, or moisture, to the air.

Humidistat:  The device that measures humidity and turns the humidifier on and off.

Humidity:  Dampness in the air caused by water vapor.

HVAC: Acronym for Heating, Ventilation, Air Conditioning. An industry label often used to refer to any one of those terms. Sometimes also HVACR, the R meaning Refrigeration.

Hybrid Comfort System: A home comfort system that combines a heat pump with a gas furnace (also available in packaged systems). For areas with colder temperatures, combining electric heating (heat pump) with gas heating (furnace) lets you choose from two fuel sources in order to respond to fluctuations in utility costs.

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IECC 2009: Standards published by the International Code Council, the IECC sets forth compliance methods for energy-efficient construction of both residential and nonresidential construction

Ignition:  Elevating the temperature of a substance to the point of causing a combustion reaction.

IHACI or Institute of Heating and Air Conditioning Industries: A nonprofit trade association of contractors, manufacturers, distributors, utilities, and related businesses actively engaged in the heating, ventilation, air conditioning, refrigeration, and sheet metal industries dedicated to the education, promotion and growth of the HVAC industry.

Indoor/Outdoor System: Refers to a comfort system consisting of components in two locations. Common examples include an outside unit, such as an air conditioner, and an indoor unit, such as a furnace with a coil.

Indoor Coil The other, less visible half of your outdoor unit. It's attached to your furnace or air handler. As indoor air flows across it, heat and moisture are drawn out, leaving air that is cool, comfortable and conditioned.

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Latent Heat:  A type of heat that when added to an area produces an effect other than an increase in temperature.

Load Calculation: A detailed analysis of your home's energy needs conducted by your dealer to help determine which comfort system is best for your home.

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Matched System: A heating and cooling system wherein all components are matched in capacity and efficiency. This enables your system to perform at its best, and most efficient, for longer.

Manufacturer’s Certification Statement: is a signed statement from the manufacturer certifying that the product or component qualifies for the tax credit. The IRS encourages manufacturers to provide these Certifications on their website to facilitate identification of qualified products. Taxpayers must keep a copy of the certification statement for their records, but do not have to submit a copy with their tax return.

Media:  The fine material of a filter that traps dirt, dust, mildew or bacteria.

Micron: A unit of measure for the smallest of the small, One Micron is 0.001 mm or 0.00004 inches. The width of a human hair is about 70 microns. Our eyes can see no smaller than 40 microns, and you’ll need a decent microscope to see a particle 20 microns wide. Allergens like dust, smoke and bacteria are particulates that are often .3 microns or less. At that size, they can get deep into your lungs, because they aren’t filtered well by your nose and throat.

Modulating Heating: Fully modulating heating provides greater fuel efficiency and ideal comfort control by constantly adjusting to changing temperatures in your home.

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NATE:  (North American Technician Excellence) is the only non-profit, independent, national certification and testing program for HVAC/R technicians accepted by the entire industry.

NCI or National Comfort Institute: An organization that provides heating, air conditioning, plumbing and electrical contractors with a focused offering of services and tools to help them improve their businesses, differentiate themselves, grow, and become more profitable.

NEC:  National Energy Council / National Electric Code

NEMA:  National Electrical Manufacturing Association

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Oil Furnace: A furnace is a part of the heating system in which the combustion of fossil fuel and transfer of heat occurs. Furnaces can be fueled by natural gas or oil.

Orifice:  An opening or hole.

Ozone: Ozone is a highly reactive gas with three oxygen molecules that affects us in good and bad ways. High up in the upper atmosphere, ozone protects us from damaging electromagnetic radiation from space. But here on Earth, ozone is an air pollutant that can damage lungs and burn sensitive plants.

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Packaged System: An outdoor unit combined with an indoor unit. A packaged central air conditioner has the evaporator coil, condenser, and compressor all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation. This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace. This combination of the air conditioner and central heater eliminates the need for a separate furnace indoors.

Particulates: A label used for tiny particles that are often invisible to the naked eye. Allergens like dust, smoke and bacteria are particulates that are often .3 microns or less. At that size, they can get deep into your lungs, because they aren’t filtered well by your nose and throat.

Principal Residence: This is the home where you live most of the time. A temporary absence due to special circumstances, such as illness, education, business, military service, or vacation will not change your principal residence.

PSI:  Pounds per square inch

PSIA:  Pounds per square inch, absolute

PSIG:  Pounds per square inch gauge

PVC:  Polyvinyl chloride; a type of plastic.

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Reciprocating Compressor:  A type of compressor used in cooling systems to compress refrigerant by using a piston action.

Refrigerant:  A chemical that condenses from a vapor to liquid and, in the process, decreases in temperature.

Refrigerant Charge:  The amount of refrigerant in a system.

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SEER (Seasonal Energy Efficiency Ratio):  A rating system developed by the U.S. Government to indicate the efficiency level of cooling equipment.

Self-contained System:  A package unit.

Sensible Heat:  Heat added or subtracted that causes a change in temperature.

Sensor:  A device that reacts to a change in conditions.

SHGC (Solar Heat Gain Coefficient): Measures how well a window blocks heat from sunlight. The lower the SHGC, the lower the heat gain through a window. SHGC ranges from 0 to 1.

Smart Home: A smart home features an advanced system that offers remote or automatic control of the systems around your home, including but not limited to, your HVAC system, lighting or security system.

Split System:  An outdoor unit combined with an indoor unit. A packaged central air conditioner has the evaporator coil, condenser, and compressor all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation. This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace. This combination of the air conditioner and central heater eliminates the need for a separate furnace indoors.

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Thermal Efficiency For energy-conversion heating devices their peak steady-state "thermal efficiency" is often stated, e.g., 'this furnace is 90% efficient', but a more detailed measure of seasonal energy efficiency is the Annual Fuel Utilization Efficiency (AFUE).

Thermostat:  Sensors that monitor and control the output of an HVAC system.

Thermostatic Expansion Valve:  A device that creates a constant evaporator temperature.

Ton:  One ton is 12,000 BTUs per hour.

Two-stage Heating / Two-stage Cooling: Two-stage heating and cooling are considered to be more efficient because it operates at a low, energy-saving speed most of the time. However, on days when more heating or cooling is required, it switches to the next stage for maximum comfort.

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U-Factor Measures how well a window, door, or skylight prevents heat from escaping. It is similar to the R-value for insulation. The lower the number, the more efficient the window. Ratings usually range from 0.20 to 1.20.

Upflow Furnace:  A furnace that pulls in air from the bottom and releases it through the top.

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Vacuum:  A space where the pressure is significantly below that of standard atmospheric pressure.

Variable-Speed Motor: The fan motor inside higher efficiency indoor and outdoor units are designed to change its speed based on your home's heating and air conditioning requirements. Working in conjunction with your thermostat, it keeps the appropriate-temperature air (e.g., warm air on cold days) circulating throughout your home, reducing temperature variances. The variable-speed motor also increases dehumidification and is quiet because it runs at a lower speed most of the time. Plus, the consistent air circulation eliminates noisy startups and shutdowns.

Volt:  A unit of electro-motive force.

Voltage:  The force pushing an electrical current along wires and cables.

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Watt:  The unit of electrical power equal to the flow of one amp at a potential difference of one volt.

Wet Bulb Thermometer:  A thermometer that measures the relative humidity in the air.

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Zoning:  A system that divides a home, office or space into different regions in order to better control the temperature and effectiveness of a heating and cooling system.

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